The name of a metal complex is written by writing the name of metal followed by its oxidation state and then the name of the anion bonded
a) Mn(NO₃)₂ : the metal is Manganese, the anion is nitrate and oxidation state of Mn is +2
so the correct name is Manganese(II) nitrate : correct option
b) Mg(NO₃)₂ : we can call it as Magnesium nitrate however it should be named as Magnesium(II) nitrate
c) Mg₃N₂ : the metal is Magnesium
However the anion is "nitride"
Hence the given name Magnesium nitrite is wrong
It should be : Magnesium (II) nitride
d) Mn(NO₂)₂ : The metal is Manganese , the oxidation state is two and the anion is Nitrite
Hence correct name is Manganese(II)nitrite
e) mg(mno4)2
The metal is Magnesium
the oxidation state is two
and thus name is
Magnesium permanganate
So completely wrong formula / name pair is Mg₃N₂:Magnesium nitrite
